Numerator

Population

Caveats and Limitations

The questions regarding mammography are part of a series of questions asked every other year in the BRFSS questionnaire, on the even years. States have the option to include the questions in the odd years in which they are not in the standard questionnaire. For those states in those years that opt to include the questions, the estimates represent annual averages of a greater number of years. Estimates that end on an odd year are not provided through the HIW.

Methodology

Based on the BRFSS questions: "A mammogram is an x-ray of each breast to look for breast cancer. Have you ever had a mammogram?" and "How long has it been since you had your last mammogram?"

In 2011, two methodological refinements were made to the Behavioral Risk Factor Surveillance System (BRFSS). The first was to expand the sample to include data received from cell phone users. This change was made to reflect the population better. The second change was to modify the statistical method to weight BRFSS survey data. The new approach simultaneously adjusts survey respondent data to known proportions of demographics such as age, race and ethnicity, and gender. Prior to 2011, the weighting method was post stratification, while in 2011 it is raking. Raking is better able to account for more demographic characteristics and multiple sampling frames. Because of these changes, data collected in 2011 and later cannot be appropriately compared to previous data, although new results should better reflect the health status of the United States (see {link:60739}).

In order to create multi-year estimates, two changes were made to the new data. First, respondents who only have cell phones were removed. Second, weights were created specifically for this purpose using the post stratification method. Those two changes make the 2011 data similar to the pre-2011 data and allowed multi-year estimates to be created, even though these estimates will not be as representative of the U.S. population as the single-year estimates using 2011 data without these changes.

Efforts to create a new small area estimate methodology that will allow use all of the improvements instigated with the 2011 data are currently taking place. Once available, that methodology will be used for estimates provided here.

This Indicator uses Age-Adjustment Groups: 50-64, 65-74, 75+

For Years 2002, 2006, 2008: data available for all states. For Year 2001: data only available for: Arizona, Arkansas, Colorado, Georgia, Hawaii, Mississippi, New Jersey, Oklahoma, Rhode Island, South Dakota, Tennessee, Wisconsin, Wyoming. For Year 2003: data only available for: Arkansas, Georgia, Hawaii, Iowa, Mississippi, Missouri, New Jersey, Oklahoma, South Dakota, Tennessee, Vermont, Wyoming. For Year 2004: data available for all states except Hawaii. For Year 2005: data only available for: Arkansas, Georgia, Iowa, Maine, Mississippi, Nevada, New Jersey, Tennessee, Vermont, Virginia, Wyoming. For Year 2007: data only available for: Arkansas, Delaware, Florida, Georgia, Hawaii, Nevada, Tennessee, Wyoming. For Year 2009: data only available for: Georgia, Hawaii, Tennessee, and Wyoming.

Estimates based on fewer than 50 cases or with a confidence interval half-width of 10% or more ((upper CI-lower CI/100) >10) are considered unreliable and are not displayed.

Data Source(s)

Behavioral Risk Factor Surveillance System (BRFSS)

Description
The Behavioral Risk Factor Surveillance System (BRFSS) is a state-based system of telephone health surveys that collects information on health risk behaviors, preventive health practices, and health care access primarily related to chronic disease and injury. The survey was established in 1984. Data are collected monthly in all 50 states, Puerto Rico, the U.S. Virgin islands, and Guam.

MethodologyData collection is conducted separately by each state. The design uses state-level, random digit dialed probability samples of the adult (aged 18 and older) population. All projects use a disproportionate stratified sample design except for Guam, Puerto Rico, and the U.S. Virgin Islands who use a simple random sample design. The questionnaire consists of three parts: (1) a core component of questions used by all states, which includes questions on demographics, and current health-related conditions and behaviors; (2) optional CDC modules on specific topics (e.g., cardiovascular disease, arthritis), that states may elect to use; and (3) state-added questions, developed by states for their own use. The state-added questions are not edited or evaluated by CDC. Interviews are generally conducted using computer-assisted telephone interviewing (CATI) systems. Data are weighted for noncoverage and nonresponse.